Sundial



July 4, 1939. w, w, LEmERT 2,164,532

SUNDIAL Original Filed Sept. 29, 1936 3 Sheets-Sheet 1 50 o go INVENTOR y 9- w. w. LEINERT I 2,164,532

SUNDIAL Oflginal Filed Sept. 29, 1936 3 She ets-Sheet 2 IN ENTOR AT 0R Y Q y 4, 1939; I w. W.VLEYINERT 2,164,532

SUNDIAL Original Filed Sept. 29, 1936 3 Sheets-Sheet INVENTOR Patented July 4, 1939 UNITED STATES wrrsnr OFFlCE Application September 29, 1936, Serial No. 103,081 Renewed November 23, 1938 Claims.

This invention relates to a sundial for getting the correct sun time and is embodied in a new, simple and decorative device and has useful and educational value. In the use of this device in- 5 structions can be given in the measurement and relationship of sun time, clock time and standard time and it also provides amusement and pleasure in its use.

The invention relates to a sundial which is placed in a proper position relative to the sun and after adjustment will register the proper sun time on an hour dial.

The invention may also include an adjustable feature by means of which the dial can be adjust- 16 ed to the latitude on which the observer is located.

The invention is also designed to combine the sun dial and a globe by which, after taking the time on a given spot, the correct time may be secured for any spot on the globe.

The invention also relates to certain details of construction which will be hereinafter more fully described and also embodiedin the claims.

The invention is illustrated in the accompanying drawings. Figure l is a face view of a sundial of my improved form mounted on a standard in conjunction with a globe. Figure 2 is a side view of the device shown in Figure 1. Figure 3 is a face view of a sundial with adjustable features for setting the dial for the desired latitude. Figure 4.- is a side view of the Sundial shown in Figure 3. Figure 5 is a detail View, enlarged, of the date dial supporting plate. Figure 6 is a section on line 6-5 in Figure 3. Figure '7 is a section on line l-! in Figure 3. Figure 8 is a section on line 5 8-8 in Figure 3.

The sundial embodies, as essential features, a ray projector or shady device, a date pointer, a pendulum for register on an hour dial and an hour dial subdivided to indicate the required subdivisions of the hour.

In my preferred embodiment of the invention the device comprises a support in the form of a housing it with a wall H forming a background for the parts. On the front of the wall I! is an 5 hour dial l2 subdivided into vertical spaces to indicate hours with the noon hour designation at one end of the dial as at !3. A date pointer i4 is pivoted to the wall H as at l5 which is in alignment at its center with the top of the noon desigignation on the hour dial and is provided with a finger it. The finger is arranged to register on a date dial H properly subdivided to indicate months as at #8 with the June and'December spaces at the ends and the intervening months properly spaced. These month spaces may be subdivided into weekly or daily subdivisions if desired. The date dial is curved to allow the pointer to swing above its face when moved by suitable finger piece as H). The parts are so arranged that the equinox is marked at a suitable point as at 20 oppOsite 'the March and September dates. A fixed slide 2| is secured on the face of the wall H and is providedwith a slot 22 the center of which slot crosses a line from the center !5 to the mark 2t exactly above the six-oclock designation onthe hour dial and perpendicular to said line. The pointer l4 passes alongside, either over or under the central raised part of the slide and is provided with a button 23 movable in the slot 22 of the slide and slidable on the pointer i5 i4 and as the pointer i4 is moved the button 23 slides with it. The button acts as a pivotal support for a pendulum 24 which is telescopic or adjustable and I show the two members 25 and 26 slidable on each other, the lower one 26 having a finger piece 2! for its manipulation. The end of the pendulum has a proper indicator such as the bead 28. On the face of the device is a sun ray projector 29 which is preferably arranged to be folded flat .1 when not in use. 25

The projector 29 has a line 30 which is aligned with a narrow slit 3! in a flap 32 which flap projects slightly at its end to enable it to be swung out by the finger. The detail mounting of this flap or tab, is shown in Figure 8. The projector is usually made of thin material such as celluloid and the flap is provided with a non-circular part 33 pivoted in a pin 34. A thin fiat spring 35 is secured to the back of the projector and holds the flap closed or open as will be evident. When in use for time determination the flap is opened and the whole device held in the position where the sun rays through the slot 3| register along the line 39. A small mark is shown at 36 in Figure 3 which is used'when the sun is near the horizon and in order to provide correct readings the beam of light should run across this point instead of along the sun-line 30. This positioning of the mark 36 compensates for the refraction of r light.

The operation of the device is as follows;

The pointer I4 is moved along the date dial I! to register on the proper mark. The flap 32 is moved to extend from the front. The frame or casing, when used by hand and alone, is held 50 in a position that results in the beam of light through the slit 3| registering along the line 30. The pendulum is swung to registerthe indicator 28 on the point I3 of the hour dial, that is on the noon designation. The pendulum is then allowed to drop and hang free and the indicator 28 will then register on the exact line for indicating correct sun time. The hour marks extend to one side of the noon designation with the numerals of the morning time at the top and the numerals of afternoon time at the bottom. This description applies to the form of sundial shown in Figures 1 and 2 with a fixed slide 2| set for a specified latitude and therefore of the simplest form.

In Figures 3 to 8 inclusive I show a sundial adapted for use within certain limits of latitude. It is the intention to provide one for the tropical zone, one for temperate zones and one for polar areas. The one illustrated is for use between 25 and 55 degrees north latitude. The casing is substantially the same comprising the frame l0, usually of light metal, with a wall II and using also the same form of hour dial l2 and pointer M, with the finger H5. The pointer is pivoted at I5 to the wall I! with its axis of movement aligned with the top of the noon designation l3.

The adjustment for latitude is made by means of a date sector 3'! which is pivoted at the pivot of the pointer and has a screw Isa which is provided with a thumb-screw 38 which is adapted to hold the date sector in position after it is adjusted. The date sector is positioned by moving it to bring the mark shown at 39 opposite the proper latitude designation shown on the latitude scale 40 which, in the present instance, reads from 25 to 55 degrees. The date sector passes through a slot 5! in the frame (see Figure 4) and is bent over to form the plate 42. The plate 62 is curved parallel to the curved top wall 43 of the casing or housing H3 and forms the support for the date scale 44' which is secured thereto by pins or rivets. The date scale there-- fore moves with the date sector and therefore also bears the same relation to the selected latitude. The date sector is moved by a stud 45 which passes through a slot 45 in the wall II' in line with the six oclock designation on the hour dial and also through a slot 4? in the date sector so that as the stud 35 is moved up or down by the finger piece 48 on the stud 45 the date sector is moved on its pivot l5a. This stud also automatically adjusts the slide as will be now described. The slide 49 consists of a front plate 59' and rear plate 51 (see Figure 7) which rear plate bears by a flange 52 on a flange 53 of the date sector 3'? and is slidable on the date sector. The stud 45 also passes through the rear plate 5| of the slide and it will be evident that as the date sector is swung the slide is slid along the date sector. The reason for this is that a slot 54 in the front plate 5% of the slide is maintained with its centre crossing the axis of stud 45, the center line of the slot ll, and perpendicular to the slot, as the flanges 53 are parallel with the slot. These parts are usually made of light metal, or Celluloid and are easily manipulated. The button 55 is slidable in the slot 54 and is slidable on the pointer 44 behind the front plate 54 of the slide and forms a pivot for the pendulum in front of the slide. Due to the slidable connection with the pointer the button can be passed freely along the slot 5 3 to allow the pointer to register on the proper date on the date scale 44'.

The pendulum 5B swings freely on its pivot 51 on the button 55 and is extensible as the lower part 58 can be slid by the finger piece 59 in the sleeves 60. The pendulum has an indicating bead 6| on its free end.

In operating this form of sundial the slotted tab 32 is swung out as shown in dotted outline in Figure 4. Then the date sector 31 is set on its proper latitude by registering the mark 39 on the scale 40. This is done by moving the stud 45 by its knob 48 which movement automatically moves the slide 49 to its proper position. The pointer I4 is now set at the proper date. Hold pendulum at 12 oclock noon on hour dial and slide the lower end of pendulum until bead 6| is at top of noon designation at l3. The device now held with the right side toward the sun until beam of light through 3| is along whole length of sun line 30. Allow pendulum to hang free just touching face of hour dial. The point over which bead hangs indicates the time. Standard or clock time can be figured by steps to be described hereinafter.

With the sundial time of sunrise or sunset for any day of the year can be read by pointing the date-sector at the latitude desired and setting the pointer at. the proper date and then holding the apparatus with the sun line horizontal and the pendulum hanging vertical to the hour lines will indicate the same as if taking a reading at sunrise or sunset.

For further educational and amusement purposes the sundial may be associated with a terrestrial globe, both rotatably mounted and by means of which one can secure the correct time for any point on the globe. It also gives the relations between sun, clock and. standard time in a concise and easily understandable way. It is of great value in instructing students about space, time and their measurements.

A compact and: easily manipulated device for the purpose is shown in Figures 1 and 2. The device comprises a foot 62 on which is rotatably mounted a bracket 63 with one arm provided with a bearing 64 in which a stud 65 can be rotatably fitted and a screw 66 used to hold the device in place. There is enough friction on the stud to keep it in adjusted positions. The stud is preferably placed in the centre of the rear face of the wall H. The form of sundial shown in Figures 3- and 4 can be similarly attached by seating the stud 65 in the opening '51 in the socket 58 in the back of the wall H.

The bracket also includes a curved arm 69 with bearings ill. The globe H is rotatably mounted in the bearings 19 by pins 12. The arm 69 is preferably provided with a latitude scale 13 corresponding with the latitude on the globe. Lines of longitude and latitude are marked on the globe and if desired the latitude can be marked on the globe instead of the scale 13. At the top of the globe is a circular plate 14 subdivided into twenty-four subdivisions representing hours. The bracket 63 can be locked against turning by locking the nut M on the screw '15 which extends down from the bracket through the foot 62 into the hollow lower part thereof.

In using the device the parts of the sundial are set as described above and the sundial tilted on the bracket until the beam of light is on the sun line. Then the sun time can be secured as above described. The sun time can be converted into clock time by adding or subtracting the difference. If the place of observation happens to be on one of the standard time meridians, viz.

th, th, th or th, the local time is alsothe standard time. If not so located, to get the standard time add or subtract from your local time 4 minutes for each degree your meridian is east or west of your standard time meridian.

Furthermore, by using the plat 14 and its hour divisions and subdivisions, by taking the suntime at one place the sun-time of any other place can be easily calculated by adding or subtracting the hours indicated in the scale H. In this way the time at any place on the globe can be determined.

The apparatus of this invention forms a compact and easily manipulated device and it will be evident that changes can be made in the form and proportion of parts without departing from the scope of the invention as set forth in the claims.

I claim:

1. A sundial comprising a support, a pivoted date sector, adate-dial on the date sector, a latitude scale secured to the support, the date sector having indicating means for registering on the latitude scale, a slide movable on the date sector, the date sector and the support having slots arranged to cross, a slot setting stud slidable in the slots for adjusting the date sector, an hour dial, a date pointer pivoted to correspond with noon on the hour dial and having a finger to register on date dial, and a pendulum supported pivotally on the slide and movable thereon in a position to indicate time on the hour dial, and a means for indicating the position for use by light from the sun.

2. A sundial comprising a back plate, a date sector pivoted to the back plate, a slide movable radially on the date sector, a fixed hour dial below the slide, the dial having a noon designation thereon, a pendulum pivoted and slidable on the slide and having extension means whereby it can be made to register with said noon designation, and an indicator for registering by shadow for positioning the device relative to the sun.

3. A sundial comprising a back plate, an hour dial on the back plate, said hour dial having spaced marks to indicate hours of antemeridian and postmeridian time with the noon indicator at one end, a marker arranged in extension of the six-hour mark, a date sector pivoted to swing relative to said noon hour designation, a date dial on said date sector, a slide movable radially on said date sector, a date pointer pivoted at the pivot of the date sector, a pendulum attached at its pivot to said date pointer, and guiding means on the slide for said pendulum attachment, said means crossing the marker, said pendulum having an indicator for indicating time on the hour dial, and a sun ray projector for positioning the device.

4. A sundial comprising a back plate, an hour dial on the back plate, said hour dial having spaced marks to indicate hours of antemeridian and postmeridian time with the noon indicator at one end, a marker arranged in extension of the six-hour mark, a date sector pivoted to swing relative to said noon hour designation, a date dial on said date sector, a slide movable radially on said date sector, a date pointer pivoted at the pivot of the date sector, a pendulum attached at its pivot to said date pointer, and guiding means on the slide for said pendulum attachment, said means crossing the marker, said pendulum having an indicator for indicating time on the hour dial, said pendulum being telescopic for registration on the noon-hour designation from pivotal situations on the slide and a sun ray projector for positioning the device.

5. A sundial comprising a support including a back plate, an hour dial on the back plate, a slide secured to the face of the back plate, a date scale, a date pointer pivoted in alignment with the noon designation on the hour dial and with a part to register on the date scale, an adjustable pendulum secured pivotally to the date pointer and arranged to register on said hour dial, and an indicator to register by shadow for positioning the device relative to the sun.

WENZEL W. LEINERTv 

